With regard to a tapered roller bearing to be used for automobiles and industrial machines, in order to deal with application of a large load or misalignment, it is required that a contact surface pressure which is generated on raceway surfaces (including rolling surfaces of rollers) of the tapered roller bearing be suppressed to an appropriate magnitude. In order to set a contact surface pressure (edge surface pressure) on the raceway surfaces of the tapered roller bearing to fall within an appropriate range, it is required that crowning be formed. Specifically, attempts have been made with various methods such as a method of forming crowning in each of an inner ring, an outer ring, and rollers and a method of forming large crowning or logarithmic crowning only in the rollers.
Among those methods, as a method which is capable of attaining the most appropriate contact surface pressure and minimizing the stress generated inside the raceway surface to extend a bearing lifetime, there have been proposed, in Patent Document 1, a logarithmic crowning function, which is obtained by modifying the Johns-Gohar's function through introduction of three design parameters thereto, and a roller bearing.
Moreover, according to Patent Document 2, with regard to a crowning shape for attaining an appropriate surface pressure, a range of a crowning drop amount at each of two points of a roller in a generating line direction from a center of a rolling element or a raceway ring is defined irrespective of the crowning shape. Further, according to Patent Document 3, there has been proposed a method of forming logarithmic crowning in a roller and forming logarithmic crowning also in any one of an inner ring and an outer ring.